Jon Stewart jogging across the street with his son ... Sienna Miller arriving at JFK ... Kiefer Sutherland walking in the West Village with his girlfriend ... Taylor Momsen going to church with her mother and sister ... Katie Lee Joel taking her dog for a walk in the Village ... Michelle Williams pushing daughter Matilda in a stroller ... Sarah Jessica Parker walking in the rain in the West Village with son James ... Hilary Duff and Mariska Hargitay hanging out on the set of Law & Order: SVU ... Sheryl Crow carrying her son Wyatt in a car seat ... and Sean Penn walking around on the set of his new movie Fair Game in Brooklyn.